1. Field of the Invention
The invention pertains to the field of cable management systems that are used to prevent tangling and resultant damage to electrical and optical cables that are used to transmit data or power. More specifically, the cable management systems are deployed to facilitate movement of one electrical chassis relative to another body without having to disconnect the cables.
2. Discussion of the Related Art
A variety of cable management systems run horizontally, as opposed to vertically. It is increasingly the case, in rack-mounted systems, that forward and rearward extensile motion of an electrical system chassis is desired without having to disconnect the cables from the chassis. The cable management systems all generate excess slack in the cables. Some degree of cable slack is required to permit the forward and rearward chassis motion; however, a relatively large amount of slack is required in practice, which becomes subject to tangling that interferes with forward and rearward motion of the chassis in horizontally-tracked systems. For example, U.S. Pat. No. 6,233,791 uses a resilient U-clip to secure cables to static surfaces. This type of fixed system does not facilitate movement of an associated electrical system chassis. U.S. Pat. No. 6,070,742 describes a horizontally extensible tray that is used to support cables in a rack mounted system; however, full inward extension of the tray is associated with the formation of cable slack that eventually develops tangles, particularly, when many different cables are present.
U.S. Pat. No. 6,170,784 discloses a variable height cable management system having a fixed horizontal brace that may be selectively attached across two upright supports. The height of the structure does not vary with motion of the associated electrical system chassis and, consequently, cable movement over the horizontal brace subjects the cables to undue wear. Furthermore, greater lengths of cable are required to accommodate the height of the horizontal support brace.
There remains a need for an improved cable management system that is capable of managing more cables and longer lengths of cables that can be managed by prior cable management systems.
The present invention overcomes the problems that are outlined above by providing a cable management system that facilitates forward and rearward motion of a rack-mounted electrical chassis. The cable management system uses articulated A-frame supports that vary with height depending upon the degree of forward and rearward motion. Thus, the cable management system is able to manage more cables and greater lengths of cables that can be managed by prior cable management systems.
The cable management system comprises an opposed pair of articulated A-frame support assemblies. Each of the articulated A-frame support assemblies comprises a first segment, a second segment, and a knee joint coupling the first segment with the second segment in a manner permitting the knee joint to move in elevation between a low position and a high position concomitant with arcuate pivoting motion of the first segment and the second segment. A cable support platform is coupled with the pair of the articulated A-frame supports to provide a horizontal surface for support of cables.
The first segment of each articulated A-frame support optionally comprises an extensible leg that permits a greater extent of forward movement in the electrical chassis. This extensible leg, for example, comprises a first member and a second member that is telescopically received within the first member. The leg is extensible when the knee joint is in the low position.
The cable support platform optionally comprises a roller. In this case, the cable support surface may include the roller having alternating cylindrical segments of different radial dimensions that act as cable groomers to distribute the load of cable across the support surface, which is bounded by cable retention ears at opposite ends of the support surface.
A single pin may extend through the roller and the knee joints of the articulated A-frame supports. The pin provides a pivot axis for the knee joints and a roller axis for the roller. A pair of spacer bearings may be borne on the pin to a greater width than is occupied by the articulated A-frame supports. The spacer bearings may abut structure, such as the interior of a rear compartment on the chassis, to prevent wobble in the cable support platform.
The cable management system is mounted on a support frame, such as the support frame for the electrical system chassis. A channel may be mounted to the support frame to provide clear access for cable installation and removal beneath other chassis components. This channel may also be provided with a tool retention structure for use in retaining a cable installation tool. A T-bar assembly may also be mounted to the support frame to provide a cable stress relief structure.
The articulated A-frame supports may each comprise a frame for use in securing cables to the articulated A-frame supports. For example, this frame may comprise a triangle brace proximate the knee joint of the articulated A-frame support. The triangle brace may be perforated to receive cable ties, cable retention clips, and the like.
The cable management system is used according to a method of managing cables to facilitate movement of the electrical system chassis assisted by use of the articulated A-frame support assembly. The method comprises the steps of:
(a) connecting a first end of a cable with the electrical system and a second end of the cable with a locus outside the electrical system such that the cable has sufficient slack to permit extensile and de-extensile motion of the electrical system chassis with respect to the locus;
(b) routing the cable over the articulated A-frame support assembly during the step of connecting; and
(c) extending and de-extending the electrical system chassis with concomitant rising and falling of the articulated A-frame support assembly to manage the slack in the cable.